Fixed ALTER TYPE to update column types

[timwmillard]

Fixed issue when ALTER TYPE does not update all the columns that uses that type. Example below does not work correctly, but does with this fix.

CREATE TYPE event AS enum ('START', 'STOP');

CREATE TABLE log_lines (
  id     BIGSERIAL    PRIMARY KEY,
  status "event"  NOT NULL
);

ALTER TYPE event RENAME TO "new_event";

-- name: ListAuthors :many
SELECT * FROM log_lines;